1. Field of the Invention
The present invention relates to a sheet metal fastener for joining a plurality of apertured panels and more particularly to a one-piece nonresiliently deformable sheet metal fastener of the dart type for joining a plurality of panels having a combined thickness within a given range.
2. Description of the Prior Art
Resilient fasteners of the dart type, usually of spring steel or resiliently deformable plastic, for joining two or more apertured panels or the like are well known in the prior art. Examples of such prior art fasteners may be seen by reference to U.S. Pat. Nos. 3,916,755; 3,959,852 and 3,412,437, the disclosures of all of which are hereby incorporated by reference.
Nonresiliently deformable, or malleable, fasteners or fastener assemblies for joining two or more apertured panels or the like are also well known in the prior art as may be seen by reference to U.S. Pat. Nos. 3,417,438; 3,108,666 and 2,732,749, the disclosures of all of which are hereby incorporated by reference.
While the prior art fasteners or fastener assemblies were generally acceptable for many purposes, they were not totally satisfactory. The resiliently deformable type required a resiliently deformable material and/or construction which was often somewhat complicated and/or expensive, were often only effective within a relatively small combined panel thickness range and/or required an insertion force which was often excessive. The nonresiliently deformable fasteners or fastener assemblies of the prior art were often of a complicated and/or expensive construction and/or required specialized assembly tooling.